1. Technical Field
The present invention relates to a transparent face temperature sensor and a transparent face temperature control apparatus. More particularly, the present invention relates to a transparent face temperature sensor adapted to control the temperature of a specimen or specimens laid thereon to a desired temperature and a transparent face temperature control apparatus including such sensor.
2. Description of the Prior Art
In the case of artificial insemination for breeding of a stock, it is often necessary to keep the temperature of the specimen such as sperm or ova to observe under the microscope. In order to satisfy such requirement, a heater for microscope had been provided. Some apparatus are recited in the Japanese patent application serial No. 6-113540 (Japanese patent No. 2835422) (1994), and Japanese utility model application serial No. 7-2714 (Japanese utility model No. 3016894) (1995).
Generally, the heater for microscope comprises a transparent plate for heater, transparent electrically conductive film deposited on the surface of the plate, for example, through deposition methods, electrodes electrically connected to the film, a transparent protective plate spaced away by a given distance from the plate, a body of a transparent insulating material such as silicone for filling the space defined between the plates, a thermocouple as a temperature sensor in which the temperature measuring junction of which is disposed between the plates, and a housing bearing the outer peripheral edge of the plates.
If it is intended to observe or examine the specimen, the heater for microscope is at first attached on the stage of the microscope, the specimen laid over the slide glass is then placed on the heater, and energizing the film to generate heat energy to warm the specimen. The current to be delivered to the heater can be controlled on the basis of the temperature detected through the thermocouple.
Various types of the heaters are available. The types of the heaters depend on the kind of microscope (e. g. an inverted microscope, an erecting microscope, or a stereomicroscope, etc.), and/or the structure (shape) of the stages of the microscopes.
The above described heater for microscope is required to keep the specimen at predetermined temperatures for all types, since this is the performance required for the heater for microscope.
The temperature-measuring junctions of the thermocouple or sensor are disposed on the end portions of the plate for heater in order not to interfere with the observation. The apparatus of this arrangement, however, tend to heat excessively on the center of the plate. Thus the temperature detected by the thermocouple is often lower than that of the central portion. In this connection the control of the temperature on the basis of the information obtained through the thermocouple may lead to the overshooting of the temperature of the central portion relative to that set.
The problem of overshooting is common with the apparatus in which the portion to be sensed in its temperature has a predetermined surface area and the temperature sensor should be insured not to interfere with the observation.